Epson LQ-2550 Technical Manual page 249

Pin No. Terminal
3 2
Vss
1, 33
XTAL
2
EXTAL
3
6 4
RESET
7
1 3 - 3 1 AO-A 18
3 4 - 4 1
6 3
6 2
ME
5 9
58
4 WAIT
6 0 E
6
5
58 HALT
61 LIR
12 ST
57
8 NMI
9 INTO
10
11
47
54 DREQ 1
55 TEND 1
45
TXAO
46 RXAO
4 2 RTSO
43 CTSO
44 DCDO
48 TXA 1
49 RXA 1
50 CKA 1
51 TXS
52 RXS
CKS
53
Table A-2. HD64180 Terminal Functions
Description
+5 VDC
I
— GND
I
External oscillator (1 2.2 MHz)
I
Pulled up
o
Reset
I
signal
Address bus (1 9-bit, 5 12K-byte)
0
Data bus (8-bit)
o Read pulse
o Write pulse
o
Memory enable
Pulled up
o
I Pulled up
o Enable (synchronous clock)
Pulled up
o Pulled up
Pulled up
o
Pulled up
o
Pulled up
o
Refresh signal
o
Pulled down
I
Pulled up
I
I Pulled
up
I Interrupt 2
Data request signal
Pulled up
Pulled up
0
Pulled up
o
Pulled up
I
SCI channel O RTS
o
I SCI channel O CTS
Pulled down
, I
i ~~~ ~~~~~~~ j
' Pulled up
o CSO 1/0 TXD
I CSO l/O RXD
CS
–
IC (7B: PB2, pin 1 1)
—
External serial l/F TXD
External serial VF RXD
A-4
Notes
ME, 4 5 )
pin
pin 37)
p i n 1 7 )
pin 19)